Hoist structure



July 13, 1943. R. H. JOHNSTON HOIST STRUCTURE Filed OCL. l0, 1940 3 Sheets-Sheet l July 13, 1943. R. H. JOHNSTON HOIST STRUCTURE Filed Oct. l0, 1940 3 sheets-sheet 2 R. H. JOHNSTON HOI ST STRUCTURE Fi'led o't. 10, 1940 5 Sheets-Sheet 5 iw www INVENTOR. Rar/vamp /z .fof/N5 my,

Patented July 13, A1943 HOIST STRUCTURE Raymond H. Johnston, Newtown, Ind., assignor to Coffing- Hoist Company, Danville, Ill., a copartnership consisting of Fredrick W. Coffing and Robert R. Bookwalter Application October 10, 1940, Serial No. 360,562

11 Claims. (Cl. 254-171) This invention relates to a hoist structure wherein there is'included a reversible, load supporting shaft rotatable in opposite directions for load elevating and load lowering.

For safety purposes, in load lowering by gravity, such hoist includes a centrifugally operable governor to prevent load dropping at too rapid a rate.

For safety purposes in load holding, et cetera, there is included a planetary arrangement and a brake arrangement.

For simplicity of construction and durability thereof, such hoist includes a unidirectional clutch of simple design associated with a disc or like clutch arrangement, operation of the latter being effected by means of a thread or screw mechanism.

The chief object of the present invention is to provide in a gravity load lowering hoist, mechanisms and arrangements broadly of the character indicated to produce a simple, safe and eilicient hoist of the character indicated.

The chief feature of the invention consists in the accomplishment of said object in the manner and by the means thus broadly designated.

'I'he hoist illustrated herein is not of free-chain character in load lowering direction but is of freechain character in load elevating direction but such hoist may by including therein mechanism of the copending joint application Serial No. 346,486, filed July 20, 1940, be transformed to a hoist capable of free-chain movement in load lowering direction when not under load.

Other objects and features will be set forth more fully hereinafter.

The full nature of the invention will be understood from the accompanying drawings and the following claims and description:

In the drawings,

Fig. 1 is a central sectional view through one embodiment of the invention.

Fig. 2 is an elevational view thereof, parts being broken away to show other parts in detail.

Fig. 3 is a side elevation of a unidirectional clutch element included in the invention, a portion of such element being broken away to show the portion in section and greater detail.

Fig. 4 is a sectional view through the clutching element.

Fig. 5 is an end elevation of the unidirectional clutch construction.

Fig. 6 is a side elevation of the speed governor mechanism included herein.

Fig. 7 is a sectional view of the brake and irnmediate control mechanism therefor.

In Figs. 1 and 2 of the drawings, the numeral 5|0 indicates a hoist housing part cooperating with part 5H to form a chamber 5|4 apertured at 5I8d to swivably support portion 5|5 of hook 5|6 by which the hoist may be suspended or supported.

These parts include a bottom opening chamber 5|9 in whichvis mounted a load sustaining sprocket chain 512 supported by sprocket teeth 520 carried by tubular shaft 52| rotatably supported at 554 and 523 by anti-friction ball race structures 691 and 596 in portions 555 and 522, respectively, of parts 5|0 and 5| Therebeneath for multiple loop chain purposes, there may be provided sprocket 538 anti-frictionally supported at 539 upon shaft 531 similarly supported by parts 5|0 and 5| If desired, one end of load chain 512 may be anchored at 51|.

Rotatably supported on portion 555 of part 5|0 is an outwardly and laterally directed portion 689 which terminates in an annular portion having external and ratchet type teeth 582. Within the same is mounted the ring gear portion 590 of a planetary system. In Fig. 2 pawl 582 pivoted upon the frame at 593 is normally constrained by spring 596 into ratchet engagement. 'I'he entire planetary system may rotate counterclockwise, see Fig. 2, but is prevented from clockwise rotation by said pawl 592 unless and until said pawl is retracted as illustrated, described and claimed in the aforesaid copending joint application. When not retractible, the hoist cannot operate as a free-chain hoist in load lowering direction when not under load.

Positioned beneath sprocket 538 is control shaft 544 intended primarily for brake control purposes as hereinafter pointed out. Shaft 544 extends into chamber forming extension 540 of housing 5|0 which is closed by plate 545.

Positioned parallel to portion 689 is pinion carrier 586 mounting shafts 581 upon which are mounted pinions 588 meshing with ring gear 590 having teeth 59|. These pinions mesh with sun gear 580 rigid with shaft 524. A plate 584 may close this gear chamber, if desired, and said chamber may be packed with lubricant. The pinion carrier plate 586 is keyed as at 586e to shaft 52| where same projects into the planetary chamber. Shaft 52| may be antifrictionally mounted on shaft 524 as at 52|a and 52|b.

Thus, power in load elevation applied to shaft 524, as hereinafter set forth, is applied through the planetary to the sprocket 520 for load chain movement and power from the load in gravity lowering is also applied to the restraint through said planetary. The applications are not the same, howeverpas hereinafter pointed out, due to" various clutches, etc. In effect it will be apparent ratchet 582 and pawl 592 constitute a clutch, the planetary being free to bodily rotate counterclockwise for load elevation-see Fig. 2-and being prevented therefrom by pawl 592 upon' attempted reverse rotation (load lowering movement).

The shaft 524 is extended beyond the planetary mechanism and its free end is rotatably supported in race 55| carried by a cup portion of a cover plate 548 secured to housing 5I0. Rotatably supported upon said shaft 524 is a plate structure 560 having a hub portion 560a directed toward the bearing 55| and a peripheral. drum forming portion 563 oppositely directed.

Associated with this hub 5601i, see Figs. 1 and 6, and rotatable thereby is a centrifugally operable governor mechanism having collar 513 with arms 513a, see Fig. 6. The weight operable arms 800 are connected at 80|-802 to adjacent ends of shoes 561 having friction lining 566 to facilitate shoe gripping of the adjacent interior surface of housing 5|0 upon attainment of predetermined load lowering speed to prevent excessive load lowering speed. A spring 803 is the governor load spring and bumpers 804 may also be provided. Such a governor structure per se is broadly illustrated and described in Patent No. 2,099,676, dated November 23, 1937.

Associated with the inwardly directed drum portion 563 of plate 560 is a brake band 564, see Figs. 1 and '7, having friction lining 565 thereon. Normally, this band is anchored (and adjustably, if desired) at one end 564a, see Fig. '7, to housing 5|0 and its opposite end is spring constrained at 564b into drum engagement. Hence, normally, the plate 560 is held against rotation by this brake. Since plate 560 does not rotate, the centrifugal brake device remains functionless. It, however, becomes operative when band 564 is released and plate 560 exceeds the predetermined speed of rotation. When shaft 544 is rocked, it, through members 8| 4, 822 and 82| releases the band from braking engagement and plate 560 is then free to rotate relative to housing 5|0 and the degree of such freedom and rotation is determined by the degree of release applied.

This release arrangement will be referred to more fully hereinafter in the description of the power application to shaft 524 and the power to the associated control to the rock-shaft 544.

Reference now will be had more particularly to Fig. 1. The drum 563 has its outer edge internally recessed at 563e. and seated therein is a drum plate 100 which is suitably anchored at a plurality of points by bolts 10|, see lower portion of Fig. 1, which draw the plate tightly to its seat. Plate 100 is centrally apertured at 102 and rotatably supported in said aperture is member 103 having on its drum enclosed end and periphery 104 the screw thread 105. The opposite end includes plate portion 106 of larger diameter than hub portion 103 but smaller in diameter than plate 100.

A plate (pressure) member 101 nested between plates 560 and 100-see Fig. l-is recessed at 108 in the face confronting the drum plate 100. Seated in this recess is the friction lining or a clutch disc 109 which, when engaging plate 100 with sufficient force, causes the drum 563 to rotate as hereinafter set forth. This plate 101 is centrally apertured and complementarily threaded as at 1 |0 to receive threaded portion 104-105,

To the free end 104 of member 103 is secured as at 1||, see Fig. 1, plate 1|2 whichat 1|3 may have contact with the pressure plate 101 adjacent the end extended as a collar.

The drum closing plate -see' Figs. l, 3, 4 and 5-at spaced points and equidistant from the axis thereof, supports a plurality of clutching arrangements. Herein each arrangement includes a spacer plate 1|5, a body plate 1|6 and a cover plate 1|1. All are apertured as at l|8 and mounted therein are rivets 1I9 which anchor said assembled members to the drum plate 100. This arrangement includes a recess 120, see Figs. 3 and 4, with a back wall 12| biased to a radius thereto. Seated in the recess is a roller 12|a `normally constrained by spring 122 seated in a recess communicating bore 123 in member 1|6. The projecting .end of the spring is associated with the roller bearing members 124 having neck portion 125 seated in the spring end. The roller thus is normally constrained toward the narrow or shallow end of the recess 120. The cover plate 1|1 may, if desired, serve as a roller retainer against accidental axial escape. The spacer plate 1|5 also may serve roller locator-see Fig. 4. Herein both features are included.

It is to be observed, see Fig. l, that in coplaner alignment with the rollers 12|a is the plate 101 and the external periphery thereof is operatively associated with said rollers. The screw member 103 is rigid-see key 103a, Fig. l-with shaft 524. The pressure plate 101 is relatively free except for the screw thread connection to the former and possible clutch connection to drum plate 100. When the two plates 101 and 100 have relative rotative movement in a direction so that the rollers move toward the shallow end of the recesses, the plates upon a predetermined amount of such movement lock together and thereafter move as a unit.

Relative movement in the opposite direction permits the rotating plate to rotate without affecting rotation of the other. This constitutes a unidirectional clutch structure of positive character and is not dependent upon tooth strength or lack of tooth strength or lack of tooth failure as required in a ratchet and pawl clutch structure which also is of unidirectional clutch character.

Now, when shaft 524, carrying the planetary sun gear 589 is rotated counterclockwise-see Fig. l-which effects load elevation, the two plates last mentioned have relative rotation in that direction and no clutch clamping occurs between the plates. When, however, shaft 524 is rotated reversely or tends so to do (incident to load lowering by gravity) the rollers 12|a engage the two members so that the two plates through the screw action are caused to engage each other through the clutch disc 109. If the brake band be not released, the load then will be held because plate 100 is rigid with drum 563 then held by the brake band 565-564.

If load holding is not desired, but load lowering is desired, the brake band is released to the desired degree and the entire governor structure and brake drum rotate in the load lowering movement. Should the control imposed by the brake fail, the increased speed of lowering transmitted to the centrifugal governor causes the shoes 566 and 561 thereof to grip the housing 5|0 for slowing down the lowering movement and thus prevent the dropping of the load.

The correlation of the screw thread associated parts and the roller clutch is such that the acrangement.

' fore the safety factor of the hoist is correspondingly increased.

Reference now will be had to the application of power to shaft 524 and the brake control ar- In Figs. 1 and 2 there is indicated a chain wheel 6 I4 which mounts an endless chain 6I6 of crossed link type and the periphery of the wheel is complementarily formed for chain reception. Carried by the housing structure is a chain guard SI1. This wheel has a plate portion 698 that is associated with portion 699 carried by housing 5I| forming a chamber therewith.

The hub 6|5 of said wheel is rotatably mounted at 6|5a on axle 524 being retained thereon by washer 649 and nut 532.

Keyed as at 6I!) to shaft 524 between the exposed wheel end of shaft 52| and the hub 6I5 is the ratchet 6| I. A pawl 6|9, see Fig. 2, is carried by the Wheel 6|4 being pivoted on plate portion 698 thereto at 62|. This pawl has the tooth 626 and the oppositely directed tooth portion 632. This pawl 6I9 is normally constrained into ratchet engagement by means not illustrated.

In the counter-clockwise rotation of chain power wheel 6| 4 by pulling down on the lefthand portion of chain 6I6, looking at Fig. 2, the pawl tooth 620, in its counter-clockwise rotation with Wheel 6I4 which carries same, picks up the ratchet 6| I and same, being keyed to shaft 524 as at SIU, is rotated counter-clockwise. 'I'his is the sole power for load elevation.

The hoist is of gravity lowering type. Of course, it has free chain action, when without load, in the load elevating direction. It may or may not have free chain action in load lowering direction when without load as previously set forth. As herein illustrated, it is not of free chain character.

Referring to Fig. 1. it is noted shaft 524 is rigid with sun gear 589, same meshing with pinion gears 588 rotatable on shafts 581 carried by plate 586 keyed at 586a to enveloping shaft 52| carrying load chain sprocket 529. The pinions 588 mesh with ring gear 59| rigid with ratchet 582. Said ratchet is normally engaged by locking pawl 592 constrained to such engagement by spring 596. This pawl 592 is the load holding pawl. This pawl permits the planetary to rotate as a unit.

In the counter-clockwise, load elevating, rotation of the sun gear, the supporting plate 586 thus is similarly rotated due to the locking reaction between the pinions and the ring gear and, hence, sprocket 520 rotates in the same direction, counterclockwise, as shaft 524.

Since the chain wheel and shaft 524 have a one-way driving connection only, reverse rotation of sprockets or load lowering cannot be effected by the direct application of power from the chain wheel 6I4 to the sprocket 520.

To lower the load. the right-hand portion of chain 6I6 is pulled down. This results in clockwise rotation of the power until the tooth 632 of pawl 6|9, see Fig. 2, carried thereby engages plunger 626a. Continued clockwise rotation, see Fig. 2, then rocks the lever 625 and shaft 544 counter-clockwise. The brake structure thus is released corresponding to the degree of rocking.

It will be recalled that shaft' 644-see Fig. 1 Y

carries the brake release mechanism in chamber 540, see Fig. '7, and projects therefrom. toward the power wheel, see Fig. 1. Keyed to said shaft 544, see Fig. 2, is an arm 625 which is socketed at 625a to receive spring 621 bearingon the inner end of plunger structure 626a, same'having an exposed end 629a terminating in a relieved f ace 629'. 'I'he plunger 626e includes a lateral pin 630 slidable in elongated slot 63|.

It is to be observed that since in this brake release or load lowering control movement the pawl 6|9 rotates clockwise, and since it ratchets upon ratchet 6II no power wheel clockwise movement is effective at any time to power rotate shaft 524 clockwise for load lowering. Slight power wheel rotation clockwise is, however, necessary for release purposes.r Such slight initial power wheel clockwise rotation separates peripherally the pawl and ring gear ratchet so that the draft interlock therebetween is removed.

In the counter-clockwise rotation of shaft 524, the relationship of the screw clutch, etc., is such that it is not effective for clutching operation, so that in load elevation, pawl 592 is a load holding element if the power is released. et cetera.

Upon reverse rotation of shaft 52 I, due to load, the screw clutch is rotated clockwise which brings the plate clutch members together and also then serves to connect through the roller clutch, the brake and governor mechanisms to the load, the lowering travel of which, as previously explained, is controlled manually through the chain wheel control of the brake and automatically through the governor structure if the manual control be accidentally actuated t drop" the load1 or an equivalent failure occur.

The hoist, therefore, may be very closely controlled for lowering, safety controlled lowering and rapidly operated for load elevating, the lowering being manually controlled but gravity actuated.

The present invention also in the dual clutch structure provides in effect a cushioning structure which permits the load to readily start lowering before the clutches become fully effective. Likewise, the clutches are of positive character hence the greater the load lowering the force applied thereto, the greater will be the clutching force generated.

The face of drum plate '|00 may be suitably grooved as at m, if desired-see Fig. 3.

While the invention has been illustrated and described in great detail in the drawings and foregoing description, the same is to be'considered as illustrative and not restrictive in character.

The several modifications described herein as well as others which will readily suggest themselves to persons skilled in this art, all are considered to be within the broad scope of the invention, reference being had to the appended claims.

The invention claimed is:

l. In a hoist having a sprocket, a load chain thereon and a housing supporting the sprocket, the combination of a sprocket supporting shaft, means for rotating the same in one direction for load elevation, a one-way clutch operatively connected to the means and shaft, a brake structure normally constrained to brake application, a control for said brake structure, a one-way clutch operatively connected to the brake structure and shaft, permitting load elevation without brake release, a second one-way clutch operatively connected to the brake structure and shaft, said second and third mentioned clutches being in series with each other, and means operable by the shaft rotating means upon predetermined movement in a direction opposite that for load elevation for effecting brake structure control operation for load lowering,

2. In a hoist having a sprocket. a load chain thereon and a housing supporting the sprocket, the combination of a sprocket supporting shaft, means for r'otating the same in one direction for load elevation, a one-way clutch operatively connected to the means and shaft, a brake structure normally constrained to brake application, a control for said brake structure, a one-way clutch operatively connected to the brake structure and shaft, permitting load elevation without brake release, a second one-way clutch operatively connected to the brake structure and shaft, said second and third mentioned clutches being in series with each other, means operable by the shaft rotating means upon predetermined movement in a direction opposite that for load elevation for effecting brake structure control operation, and a planetary structure operatively connected to the sprocket and brake structure.

3. In a hoist having a sprocket, a load chain thereon and a housing supporting the sprocket, of a sprocket supporting shaft, means for rotating the same in one direction for load elevation, a one-way clutch operatively connected to the means and shaft, a brake structure normally constrained to brake application, a control for said brake structure, a one-way clutch operatively connected to the brake structure and shaft, permitting load elevation without brake release, a second one-way clutch operatively connected to the brake structure and shaft, said second and third mentioned clutches being in series with each other, means operable by the shaft rotating means upon predetermined movement in a direction opposite that for load elevation for effecting brake structure control operation, and a pawl and ratchet arrangement operatively connected to the housing and shaft for load holding.

4. In a hoist having a sprocket, a load chain thereon and a housing supporting the sprocket, the combination of a sprocket supporting shaft, means for rotating the same in one direction for load elevation, a one-way clutch operatively connected to the means and shaft, a brake structure normally constrained to brake application, a control for said brake structure, a one-way clutch operatively connected to the brake structure and shaft, permitting load elevation Without brake release, a second one-way clutch operatively connected to the brake structure and shaft, said second and third mentioned clutches being in series'with each other, a speed operable governor brake arrangement in multiple with the first mentioned brake structure for preventing excessive load lowering speeds upon brake failure and/or accidental full release of the brake structure, means operable by the shaft rotating means upon predetermined lmovement in a direction opposite that for load elevation for effecting brake structure control operation.

5. In a hoist having a sprocket, a load chain thereon and a housing supporting the sprocket, the combination of a sprocket supporting shaft, means for rotating the same in one direction for load elevation, a one-way clutch operatively connected to the means and shaft, a brake structure normally constrained to brakey application, a control for said brake structure. a one-wav clutch operatively connected to the brake structure and shaft, permitting load elevation without brake release, a second one-way clutch operatively connected to the brake structure and shaft, said second and third mentioned clutches being in series with each other, means operable by the shaft rotating means upon predetermined movement in a direction opposite' that for load elevation for effecting brake structure control operation, a planetary structure operatively connected to the sprocket and brake structure, and a pawl and ratchet arrangement operatively connected to the housing and planetary structure permitting unitary rotation of the planetary structure in one direction of load movement andrequiring planetary action in the opposite direction of load movement.

6. In a hoist having a sprocket, a load chain thereon and a housing supporting the sprocket, the combination of a sprocket supporting shaft, means for rotating the same in one direction for load elevation, a one-way clutch operatively connected to the means and shaft, a brake structure normally constrained to brake application, a control for said brake structure, a one-way clutch operatively connected to the Ibrake structure and shaft, permitting load elevation Without brake release, a second one-way clutch operatively connected to the brake structure and shaft, said second and third mentioned clutches being in series with each other, and one of the series clutches being of the progressive pressure type, including a clutch plate, a confronting plate, said plates being relatively rotatable, a spiral feed connection for associating the plates together and with pressures corresponding to the power applied thereto, and a planetary structure operatively connected to the sprocket and brake structure.

7. In a hoist having a sprocket, a load chain thereon and a housing supporting the sprocket, the combination of a sprocket supporting shaft, means for rotating the same in one direction for load elevation, a one-way clutch operatively connected to the means and shaft, a brake structure normally constrained to brake application, a control for said brake structure, a one-way clutch operatively connected to the brake structure and shaft, permitting load elevation Without brake release, a second one-way clutch operatively connected to the brake structure and shaft, said second and third mentioned clutches being in series with each other, and one of the series clutches being of the progressive pressure type, including a clutch plate, a confronting plate, said plates being relatively rotatable, a spiral feed connection for associating the plates together and with pressures corresponding to the power applied thereto, a planetary structure operatively connected to the sprocket and brake structure, and a pawl and ratchet arrangement operatively connected to the housing and planetary structure permitting unitary rotation of the planetary structure in one direction of load movement and requiring planetary action in the opposite direction of load movement.

8. A hoist as defined by claim wherein one of the series clutches is of the progressive pressure type including a clutch plate, a confronting plate, said plates being relatively rotatable, and a spiral feed connection for associating the plates together and with pressures corresponding to the powers applied thereto.

9. A hoist as defined by claim 1 wherein one of the series clutches is of the progressive pressure type including a clutch plate, a confronting plate, said plates being relatively rotatable, and a spiral feed connection for associating the plates together and with pressures corresponding to the powers applied thereto, the other of said series clutches being of roller and inclined slot character.

10. A hoist as deiined by claim l wherein one of the series clutches is of the progressive pressure type including a clutch plate, a confronting plate, said plates being relatively rotatable, and a spiral feed connection for associating the plates together and with pressures corresponding to the power applied thereto, the rst mentioned one-way clutch being of pawl and ratchet type. 11. A hoist as dened by claim 1 wherein one of the series clutches is of the progressive pressure type including a clutch plate, a confronting plate, said plates being relatively rotatable, and a spiral feed connection for associating the plates together and with pressures corresponding to the powers applied thereto, the other of said series clutches being of roller and inclined slot character, the rst mentioned --one-way clutch being of pawl and ratchet type.

RAYMOND H. JOHNSTON. 

